diff --git a/web/database/utils/constants.js b/web/database/utils/constants.js
index f9930c2e1..0946f1297 100644
--- a/web/database/utils/constants.js
+++ b/web/database/utils/constants.js
@@ -1,4 +1,6 @@
 // @flow
 
 export const SQLITE_CONTENT = 'sqliteFileContent';
 export const SQLITE_ENCRYPTION_KEY = 'encryptionKey';
+
+export const CURRENT_USER_ID_KEY = 'current_user_id';
diff --git a/web/database/worker/db-worker.js b/web/database/worker/db-worker.js
index 5afb6d6f4..a58ada4fe 100644
--- a/web/database/worker/db-worker.js
+++ b/web/database/worker/db-worker.js
@@ -1,164 +1,184 @@
 // @flow
 
 import localforage from 'localforage';
 import initSqlJs, { type SqliteDatabase } from 'sql.js';
 
 import type {
   ClientDBDraftStoreOperation,
   DraftStoreOperation,
 } from 'lib/types/draft-types.js';
 import type { ClientDBStore } from 'lib/types/store-ops-types.js';
 
 import {
   type SharedWorkerMessageEvent,
   type WorkerRequestMessage,
   type WorkerResponseMessage,
   workerRequestMessageTypes,
   workerResponseMessageTypes,
   type WorkerRequestProxyMessage,
 } from '../../types/worker-types.js';
 import { getSQLiteDBVersion, setupSQLiteDB } from '../queries/db-queries.js';
 import {
   getAllDrafts,
   moveDraft,
   removeAllDrafts,
   updateDraft,
 } from '../queries/draft-queries.js';
-import { SQLITE_CONTENT, SQLITE_ENCRYPTION_KEY } from '../utils/constants.js';
+import { getMetadata, setMetadata } from '../queries/metadata-queries.js';
+import {
+  CURRENT_USER_ID_KEY,
+  SQLITE_CONTENT,
+  SQLITE_ENCRYPTION_KEY,
+} from '../utils/constants.js';
 import { generateDatabaseCryptoKey } from '../utils/worker-crypto-utils.js';
 
 const localforageConfig: PartialConfig = {
   driver: localforage.INDEXEDDB,
   name: 'comm',
   storeName: 'commStorage',
   description: 'Comm encrypted database storage',
   version: '1.0',
 };
 localforage.config(localforageConfig);
 
 let sqliteDb: ?SqliteDatabase = null;
 
 async function initDatabase(sqljsFilePath: string, sqljsFilename: ?string) {
   const content = await localforage.getItem(SQLITE_CONTENT);
 
   const locateFile = defaultFilename => {
     if (sqljsFilename) {
       return `${sqljsFilePath}/${sqljsFilename}`;
     }
     return `${sqljsFilePath}/${defaultFilename}`;
   };
   const SQL = await initSqlJs({
     locateFile,
   });
 
   if (content) {
     sqliteDb = new SQL.Database(new Uint8Array(content));
   } else {
     sqliteDb = new SQL.Database();
     setupSQLiteDB(sqliteDb);
   }
 
   const dbVersion = getSQLiteDBVersion(sqliteDb);
   console.info(`Db version: ${dbVersion}`);
 }
 
 function processDraftStoreOperations(
   operations: $ReadOnlyArray<ClientDBDraftStoreOperation>,
 ) {
   if (!sqliteDb) {
     throw new Error('Database not initialized');
   }
   for (const operation: DraftStoreOperation of operations) {
     if (operation.type === 'remove_all') {
       removeAllDrafts(sqliteDb);
     } else if (operation.type === 'update') {
       const { key, text } = operation.payload;
       updateDraft(sqliteDb, key, text);
     } else if (operation.type === 'move') {
       const { oldKey, newKey } = operation.payload;
       moveDraft(sqliteDb, oldKey, newKey);
     } else {
       throw new Error('Unsupported draft operation');
     }
   }
 }
 
 function getClientStore(): ClientDBStore {
   if (!sqliteDb) {
     throw new Error('Database not initialized');
   }
   return {
     drafts: getAllDrafts(sqliteDb),
     messages: [],
     threads: [],
   };
 }
 
 async function processAppRequest(
   message: WorkerRequestMessage,
 ): Promise<?WorkerResponseMessage> {
   if (message.type === workerRequestMessageTypes.PING) {
     return {
       type: workerResponseMessageTypes.PONG,
       text: 'PONG',
     };
   } else if (message.type === workerRequestMessageTypes.INIT) {
     await initDatabase(message.sqljsFilePath, message.sqljsFilename);
     return;
   } else if (
     message.type === workerRequestMessageTypes.GENERATE_DATABASE_ENCRYPTION_KEY
   ) {
     const cryptoKey = await generateDatabaseCryptoKey();
     await localforage.setItem(SQLITE_ENCRYPTION_KEY, cryptoKey);
     return;
   } else if (
     message.type === workerRequestMessageTypes.PROCESS_STORE_OPERATIONS
   ) {
     const { draftStoreOperations } = message.storeOperations;
     if (draftStoreOperations) {
       processDraftStoreOperations(draftStoreOperations);
     }
     return;
   } else if (message.type === workerRequestMessageTypes.GET_CLIENT_STORE) {
     return {
       type: workerResponseMessageTypes.CLIENT_STORE,
       store: getClientStore(),
     };
+  } else if (message.type === workerRequestMessageTypes.SET_CURRENT_USER_ID) {
+    if (!sqliteDb) {
+      throw new Error('Database not initialized');
+    }
+    setMetadata(sqliteDb, CURRENT_USER_ID_KEY, message.userID);
+    return;
+  } else if (message.type === workerRequestMessageTypes.GET_CURRENT_USER_ID) {
+    if (!sqliteDb) {
+      throw new Error('Database not initialized');
+    }
+    const userID = getMetadata(sqliteDb, CURRENT_USER_ID_KEY);
+    return {
+      type: workerResponseMessageTypes.GET_CURRENT_USER_ID,
+      userID,
+    };
   }
 
   throw new Error('Request type not supported');
 }
 
 function connectHandler(event: SharedWorkerMessageEvent) {
   if (!event.ports.length) {
     return;
   }
   const port: MessagePort = event.ports[0];
   console.log('Web database worker alive!');
 
   port.onmessage = async function (messageEvent: MessageEvent) {
     const data: WorkerRequestProxyMessage = (messageEvent.data: any);
     const { id, message } = data;
 
     if (!id) {
       port.postMessage({
         error: new Error('Request without identifier'),
       });
     }
 
     try {
       const result = await processAppRequest(message);
       port.postMessage({
         id,
         message: result,
       });
     } catch (e) {
       port.postMessage({
         id,
         error: e,
       });
     }
   };
 }
 
 self.addEventListener('connect', connectHandler);
diff --git a/web/types/worker-types.js b/web/types/worker-types.js
index 27d465dce..ef0837d33 100644
--- a/web/types/worker-types.js
+++ b/web/types/worker-types.js
@@ -1,83 +1,103 @@
 // @flow
 
 import type {
   ClientDBStore,
   ClientDBStoreOperations,
 } from 'lib/types/store-ops-types.js';
 
 // The types of messages sent from app to worker
 export const workerRequestMessageTypes = Object.freeze({
   PING: 0,
   INIT: 1,
   GENERATE_DATABASE_ENCRYPTION_KEY: 2,
   PROCESS_STORE_OPERATIONS: 3,
   GET_CLIENT_STORE: 4,
+  SET_CURRENT_USER_ID: 5,
+  GET_CURRENT_USER_ID: 6,
 });
 
 export type PingWorkerRequestMessage = {
   +type: 0,
   +text: string,
 };
 
 export type InitWorkerRequestMessage = {
   +type: 1,
   +sqljsFilePath: string,
   +sqljsFilename: ?string,
 };
 
 export type GenerateDatabaseEncryptionKeyRequestMessage = {
   +type: 2,
 };
 
 export type ProcessStoreOperationsRequestMessage = {
   +type: 3,
   +storeOperations: ClientDBStoreOperations,
 };
 
 export type GetClientStoreRequestMessage = {
   +type: 4,
 };
 
+export type SetCurrentUserIDRequestMessage = {
+  +type: 5,
+  +userID: string,
+};
+
+export type GetCurrentUserIDRequestMessage = {
+  +type: 6,
+};
+
 export type WorkerRequestMessage =
   | PingWorkerRequestMessage
   | InitWorkerRequestMessage
   | GenerateDatabaseEncryptionKeyRequestMessage
   | ProcessStoreOperationsRequestMessage
-  | GetClientStoreRequestMessage;
+  | GetClientStoreRequestMessage
+  | SetCurrentUserIDRequestMessage
+  | GetCurrentUserIDRequestMessage;
 
 export type WorkerRequestProxyMessage = {
   +id: number,
   +message: WorkerRequestMessage,
 };
 
 // The types of messages sent from worker to app
 export const workerResponseMessageTypes = Object.freeze({
   PONG: 0,
   CLIENT_STORE: 1,
+  GET_CURRENT_USER_ID: 2,
 });
 
 export type PongWorkerResponseMessage = {
   +type: 0,
   +text: string,
 };
 
 export type ClientStoreResponseMessage = {
   +type: 1,
   +store: ClientDBStore,
 };
 
+export type GetCurrentUserIDResponseMessage = {
+  +type: 2,
+  +userID: ?string,
+};
+
 export type WorkerResponseMessage =
   | PongWorkerResponseMessage
-  | ClientStoreResponseMessage;
+  | ClientStoreResponseMessage
+  | GetCurrentUserIDResponseMessage;
 
 export type WorkerResponseProxyMessage = {
   +id?: number,
   +message?: WorkerResponseMessage,
   +error?: Error,
 };
 
 // SharedWorker types
 export type SharedWorkerMessageEvent = MessageEvent & {
   +ports: $ReadOnlyArray<MessagePort>,
   ...
 };